Dunglass Castle is now fragmentary having been despoiled upon an order by the Commissioners of Supply in 1735 to use it as a quarry for repairing the quay. The castle, of the period 1400-1542 and courtyard plan now consists of the remains of a high wall enclosing the top of the cliff and mixed in parts with modern work. Of this wall the major portions are in the south and west walls against which buildings were formerly erected. Near the west end of, and outside the south wall is a small landing place appearing to have been protected by a hoarding - some corbels for which still remain. At the NW corner of the enclosure is a dwelling house, partly old, possibly circa 1590, but mostly modern - the interior is wholly so.

The round tower is probably 17th century and appears to have been a pigeon house.

D MacGibbon and T Ross 1889

The remains of Dunglass Castle are as described above. The walls remain to approximately 7-8 metres high but the portion of the south wall from the ruined outhouse to the dovecot - from NS 4374 7349 to NS 4376 7349 - fell into the river circa 1910 - 20 and has been rebuilt. The conical dovecot still stands.

Site Management (21 February 1990)

Fragmentary castle standing on an irregular rocky cliff by the River Clyde. A dwelling house has been erected at the north west corner of the enclosure, partly old, mostly modern; north west turret has chequered corbelling. The round tower in opposite corner is probably 17th century and appears to have been a pigeon house. (Historic Scotland)

The old castle dates back to 1380, when it was the important strategic stronghold of the barony of Colquhoun. In the early 18th century it fell into neglect and was partly dismantled for the restoration of the Bowling quay. This was halted by Andrew Buchanan of Auchentorlie, who bought the property in 1812. It now stands as a fragementary castle situated on a rocky cliff by the River Clyde. The north west turret has chequered corbelling and bears the Colquhoun arms along with other devices, whilst the round south east turret is probably 17th century in date and may have been a pigeon roost. A dwelling house (now demolished) sat in the north west corner of the enclosure, incorporating older elements but mostly post-1812 in date. A doocot sits adjacent, whilst an obelisk memorial to Henry Bell also sits within the grounds.

The castle has strong links to the Glasgow Style, and was previously occupied by the graphic artist Talwin Morris (1865-1911) who became the graphic designer for Glasgow publishers Blackie and Son. Morris invited Charles Rennie Mackintosh to design the interiors. The castle's bookcase is now in the collection of the Royal Museum, Edinburgh and all other interior fittings have been removed. Mackintosh's work here led to his commission for the Hillhouse in Helensburgh.